1.
目前使用线程池对象建立了两个线程，然后，放在线程池中，其中一个线程已经完成，另一个线程还在激活状态，进行执行：
exec的对象始终调用的是当前的线程，进行调用，其中线程是通过引用存放在线程池中的
显示结果如下所示：
"C:\Program Files\Java\jdk1.8.0_171\bin\java.exe" "-javaagent:D:\IDEA_JAVA\IntelliJ IDEA 2018.2.4\lib\idea_rt.jar=57309:D:\IDEA_JAVA\IntelliJ IDEA 2018.2.4\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_171\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_171\jre\lib\rt.jar;C:\Users\wu\Desktop\work\11\vue\并发\out\production\并发" CachedThreadPool
#0(9)
#1(9)
#0(8)
#2(9)
#3(9)
#4(9)
#1(8)
#0(7)
#2(8)
#3(8)
#4(8)
#1(7)
#0(6)
#3(7)
#2(7)
#4(7)
#1(6)
#0(5)
#3(6)
#2(6)
#4(6)
#1(5)
#0(4)
#3(5)
#2(5)
#4(5)
#1(4)
#0(3)
#3(4)
#2(4)
#1(3)
#4(4)
#0(2)
#3(3)
#2(3)
#1(2)
#4(3)
#0(1)
#3(2)
#2(2)
#1(1)
#4(2)
#0(liftOff!)
#3(1)
#2(1)
#1(liftOff!)
#4(1)
#3(liftOff!)
#2(liftOff!)
#4(liftOff!)
Process finished with exit code 0
显示结果如上所示：会优先去调度使用占用资源比较多的线程，然后再去调用线程执行比较少的资源：
结果显示如下所示：
详细实现验证代码，实现结果如下所示：
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class CachedThreadPool {
public static void main(String[] args){
ExecutorService exec= Executors.newFixedThreadPool(3);//使用有限线程去调度，使用优先级高，耗资源的先进行调用。
for (int i=0;i<5;i++){
exec.execute(new LiftOff());
}
exec.shutdown();
}
}
public class LiftOff implements Runnable{
protected int CountDown =10;//3
private static int taskcount=0;//1
private final int id=taskcount++;//4
public LiftOff(){}//2
public LiftOff(int CountDown){
this.CountDown=CountDown;
}
public String status(){ //判断条件以及验证状态
return "#"+id+"("+(CountDown>0?CountDown:"liftOff!")+")";
}
public void run(){ //执行
while (CountDown-->0){//将CountDown进行自减操作：
System.out.println(status());
Thread.yield();
}
}
}